Engine RPM signal

Engine RPM signal

This is supplied from the injection/ignition control unit. The engine torque is calculated from the RPM signal.

The same signal is used to prevent engine starting when the vehicle is pushed or towed.

Accelerator pedal switch

This sends an alert signal indicating that the driver wants to move the vehicle, before the throttle valve starts to open.

The vehicle moves only after this signal has been supplied.

Throttle valve position sensor

This potentiometer sends a signal to regulate the clutch torque variation as a function of the engine RPM and throttle opening.

"D" "L" and "R" position sensing switches

These switches allow the clutch control unit to sense the selected driving mode and then engage or disengage the clutch.

Vehicle speed sensor

As a result of this signal, the clutch is completely engaged when the vehicle speed reaches 20 km/h in "L" or "R" and 35 km/h in "D".

The sensor reads the rotation speed of the parking gear.

Water temperature sensor signal

When this signal indicates that the engine is "cold", the control unit increases the current sent to the clutch to raise the lockup point.

If the clutch rotates below the lockup point then slippage occurs. If it rotates at above the lockup point then it is locked solid.

Air conditioner sensor signal

This signal indicates that the air conditioner is operating. The control unit then compensates the clutch current. (The clutch torque is reduced when the engine torque is reduced).

Brake switch

Braking is signalled for the following reasons:

1. To disengage the clutch, hence preventing engine stalling if the wheels lock.
2. To increase the hydraulic pulley closing pressure to prevent damage to the belt following wheel locking.

Torque signal (2nd accelerator pedal switch)

This signal is used to increase or decrease the hydraulic circuit pressure, depending on the engine torque.

The engine torque is calculated by the transmission control unit as a function of the engine RPM, the air flow rate, the water temperature, etc.